Directional boring systems and methods

Abstract

Directional drilling technologies and methodologies involve/utilize a reamer embodying a pressure vessel configured for directing flows of fresh mud through the reamer/pressure vessel and toward an entry side of a bore hole being drilled by the reamer, facilitating single ream pass directional drilling of bore holes, and preventing the reamer from deviating from the path of the pilot hole.

What is claimed is: 
     
         1 . A reamer for drilling a bore hole, comprising:
 an assembly of fluidically interconnected chambers with a channel therethrough including seals, the channel being configured to receive a pilot drill pipe and to allow the reamer to advance along a drill path defined by the pilot drill pipe, the assembly of chambers and at least one of the seals being configured such that a flow of fresh mud entering the assembly, via openings in a proximal end chamber of the assembly, is routed through the assembly to exit via cutter jets of the reamer at locations external to the chambers and within the bore hole being drilled.   
     
     
         2 . The reamer of  claim 1 , wherein the seals are configured to fit about the pilot drill pipe and serve as rotary bearings supporting the reamer as the reamer is advanced along the pilot drill pipe. 
     
     
         3 . The reamer of  claim 1 , wherein portions of the assembly include openings that fluidically interconnect the chambers; and said at least one seal is secured within a distal portion of an innermost chamber of the assembly. 
     
     
         4 . The reamer of  claim 3 , wherein the openings are located in housings of the chambers and in one or more of the seals and/or in one or more seal mounts peripherally supporting the seals. 
     
     
         5 . The reamer of  claim 3 , wherein said at least one seal spans between the channel and the pilot drill pipe when the pilot drill pipe is received within the channel. 
     
     
         6 . The reamer of  claim 3 , wherein the innermost chamber includes a housing having openings fluidically interconnecting the innermost chamber to three or more other chambers of the assembly. 
     
     
         7 . The reamer of  claim 1 , wherein portions of the assembly include exit ports fluidically interconnecting the chambers with the cutter jets. 
     
     
         8 . The reamer of  claim 1 , wherein the proximal end chamber is an outermost chamber of the assembly in respect to the channel. 
     
     
         9 . The reamer of  claim 1 , wherein the proximal end chamber is dome-shaped. 
     
     
         10 . The reamer of  claim 1 , wherein the assembly includes a conical periphery structure at a proximal end of the assembly. 
     
     
         11 . A method for directional drilling a bore hole with a single ream pass, comprising the steps of:
 advancing a pilot pipe from an exit side to an entry side in relation to respective ends of a bore hole to be drilled, and then securing the pilot pipe at the entrance side and/or at the exit side; and   utilizing a drill pipe and a reamer to ream the bore hole advancing along the pilot drill pipe while directing a flow of fresh mud through the reamer to exit via cutter jets of the reamer and toward the entry side of the bore hole being drilled.   
     
     
         12 . The method of  claim 11 , further comprising:
 once the reamer reaches the exit side, removing the reamer from the drill pipe.   
     
     
         13 . The method of  claim 12 , further comprising:
 performing a swab pass to clean the bore hole while leaving the pilot pipe in the bore hole.   
     
     
         14 . The method of  claim 12 , further comprising:
 using the pilot pipe to pull a product pipe in the bore hole, or replacing the pilot pipe with the drill pipe and using the drill pipe to pull the product pipe through the bore hole to the entry side.   
     
     
         15 . The method of  claim 11 , further comprising:
 collecting mudflow, that is spoils mud, exiting from the bore hole at the entry side; and   cleaning solids from the spoils mud to provide fresh mud and adjusting properties of the fresh mud.   
     
     
         16 . The method of  claim 15 , wherein the step of adjusting properties of the fresh mud is performed based on a priori knowledge of geological characteristics at the present location and/or soon/next to be drilled locations in respect to the reamer. 
     
     
         17 . The method of  claim 15 , further comprising:
 pumping the fresh mud into the drill pipe from the entry side as needed to maintain a desired pressurization of a pressure vessel defined by the reamer such that a flow of fresh mud entering the pressure vessel, via openings in a proximal end chamber of the reamer, is routed through the pressure vessel/reamer to exit via cutter jets of the reamer at locations external to the reamer and within the bore hole being drilled.   
     
     
         18 . The method of  claim 17 , further comprising:
 supplementing the fresh mud as needed by pumping additional fresh mud from the exit side through the pilot pipe into the drill pipe.   
     
     
         19 . A horizontal directional drilling apparatus comprising:
 a reamer including
 a plurality of fluidically interconnected chambers providing a housing exterior having a sequence of surfaces supporting cutting bits, the surfaces increasing in circumference along the sequence toward a proximal end portion of the reamer, 
 a channel that extends longitudinally through the reamer between a distal end portion and the proximal end portion thereof, the channel being defined at the distal end portion by an inner-most chamber of the plurality of chambers, the channel being configured to receive a pilot drill pipe and to allow the reamer to advance along a drill path defined by the pilot drill pipe, and 
 a sealing device within, couple to and peripherally supported by the inner-most chamber, the sealing device including an annular inner portion sized to receive and closely fit about the pilot drill pipe, the sealing device spanning between the channel and the pilot drill pipe when the pilot drill pipe is received within the channel, 
 wherein the fluidically interconnected chambers and the sealing device are configured to provide a pressure vessel that directs a flow of fresh mud entering the reamer at the proximal end portion thereof through the chambers to exit via cutter jets of the cutting bits at locations external to the chambers and within a bore hole being drilled by the reamer and toward an entry side of the bore hole. 
   
     
     
         20 . The horizontal directional drilling apparatus of  claim 19 , wherein the plurality of fluidically interconnected chambers includes four or more chambers. 
     
     
         21 . The horizontal directional drilling apparatus of  claim 19 , wherein the surfaces of the housing exterior—from the distal end of the reamer—are circumferentially nested and sequentially increase in radial distance from the channel moving along the reamer toward the proximal end portion of the reamer. 
     
     
         22 . The horizontal directional drilling apparatus of  claim 19 , wherein the reamer includes a coupler configured for connecting the plurality of nested fluidically interconnected chambers to a drill pipe that rotates and drives the reamer.